@article {Toumajrheum.110550, author = {Zahi Touma and Dafna D. Gladman and Dominique Iba{\~n}ez and Shahrzad Taghavi-Zadeh and Murray B. Urowitz}, title = {Systemic Lupus Erythematosus Disease Activity Index 2000 Responder Index-50 Enhances the Ability of SLE Responder Index to Identify Responders in Clinical Trials}, elocation-id = {jrheum.110550}, year = {2011}, doi = {10.3899/jrheum.110550}, publisher = {The Journal of Rheumatology}, abstract = {Objective To evaluate the performance of the Systemic Lupus Erythematosus (SLE) Responder Index (SRI) when the SLE Disease Activity Index 2000 (SLEDAI-2K) is substituted with SLEDAI-2K Responder Index-50 (SRI-50), a valid and reliable index of disease activity improvement. Also, to determine whether the SRI-50 will enhance the ability of SRI in detecting responders. Methods Our study was conducted on patients who attended the Lupus Clinic from September 2009 to September 2010. SLEDAI-2K, SRI-50, the British Isles Lupus Assessment Group measure, and the Physician{\textquoteright}s Global Assessment were determined initially and at followup. SRI was determined at the followup visit according to its original definition using the SLEDAI-2K score and by substituting SLEDAI-2K with SRI-50. Results A total of 117 patients with SLEDAI-2K >= 4 at baseline were studied. Patients had 1 followup visit over a 3-month period. Twenty-nine percent of patients met the original definition of SRI and 35\% of patients met the definition of SRI when SLEDAI-2K was substituted with SRI-50. The use of SRI-50 allowed determination of significant improvement in 7 additional patients. This improvement could not be discerned with the use of SLEDAI-2K as a component of SRI. At followup visits that showed improvement, SRI-50 scores decreased to a greater extent than SLEDAI-2K scores (p \< 0.0001). Conclusion SRI-50 enhances the ability of SRI to identify patients with clinically important improvement in disease activity. SRI-50 was superior to SLEDAI-2K in detecting partial clinical improvement, >= 50\%, between visits. These properties of the SRI-50 enable it to be used as an independent outcome measure of improvement or as a component of SRI in clinical trials.}, issn = {0315-162X}, URL = {https://www.jrheum.org/content/early/2011/08/30/jrheum.110550}, eprint = {https://www.jrheum.org/content/early/2011/08/30/jrheum.110550.full.pdf}, journal = {The Journal of Rheumatology} }